42 PRESIDENTIAL ADDRESS SECTION 1!. 



Huxley published their classic researches, and which have later 

 been studied so closely by Professor R. Broom. Some sixty- 

 four species of reptilia have been listed by Dr. Rogers. 



All these genera swarmed the plains and jungles of Gond- 

 wanaland, and one South African reached India; other groups 

 developed new forms in transit — so that there is little difference 

 between the Indian and South African faunas. Some passed 

 along the isthmus to the north, for forms typically Karroo have 

 been found in Permian strata in Russia. Mcsosannis has been 

 found in Brazil. 



Karroo reptiles are, however, absent from Australia, and 

 this may be due to break in the land connections to the east, 

 passable to plants but not to animals. Yet they visited Rhodesia, 

 for limestones on the Sengwe coal-field have yielded fragments 

 of their bones. Near Broken Hill very fragmentary remains 

 have been found in the later beds of the Luana coal-field, and 

 Professor Broom has kindly examined them for me. He says 

 that the deposit in which they are buried is not older than 

 Permian or younger than Upper Triassic. There are small 

 pointed teeth that may be those of either therocephalians, 

 cynodonts or carnivorous dinosaurs, the little evidence there is 

 being in favour of the deposit being either Upper Triassic 

 ( Burghersdorp beds), Molteno or Stormberg. 



Other evidences of fresh-water conditions of the Rhodesian 

 Karroo strata are the occurrence of the ganoid fishes (Acrolcpis) 

 and their scales, the little o.stracoid crustacean Esfhcria, and the 

 small bivalve mollusc palccomutelo — all referable to the Permo- 

 Carboniferous Age, and being represented in similar beds in 

 Russia. The evidence of the geographical link with the northern 

 Permian continent is thus complete, for any salt-water ])reak 

 would have been impossible to negotiate by the fresh-water 

 denizens. 



Probable Extent of an Ancient Continent. 



The geographical extent of Gondwanaland is thus attested 

 by fauna, flora, and general continental conditions, and though 

 the various provinces are now separated by stretches of the 

 deep, the vegetable and animal prototypes developed therein had 

 a remarkable influence on the descent of the species of the pre- 

 sent time, which possess a striking affinity in South America, 

 Australia and South Africa, of which birds of the ostrich type 

 are specially of notice. Diprotodont marsupials are represented 

 in South America as well as occurring as abundant fossil remains 

 in Australia, their dying out and disappearance from South 

 Africa suggesting an early break of the land bridge. Fossil 

 remains in Patagonia and Tasmania represent similar types, the 

 absence of which from India and South Africa suggest that their 

 distribution was by way of an even greater continental region 

 to the south. 



The exploration of the Antarctic continent is thus of deep 

 interest to the South African geologist and geographer, and may 

 be again referred to in view of the problems confronting us. 



